Sealing a Vinyl Sliding Window
- 1). Wait for a particularly windy or cold day to check your windows for failed seals around the windowpanes. Hold your hand over the pane from inside the structure to detect any airflow through the edges of the pane past failed seals. Mark these locations with a piece of soap, making an “X” across the affected pane.
- 2). Seal the marked pane from both sides by applying a bead of caulking around the edges of the pane, against the frame holding the pane in place. Smooth the caulk with a wet fingertip to make the bead as neat as possible.
- 3). Seal the base of the window where the bottom sash meets the sill, if the draft appears to come from that area, using weather stripping foam tape. Lift the sash upward about 4 inches. Measure the length of the window base where the sash meets the sill with a tape measure. Cut a piece of the foam tape to match the measured length with a pair of scissors. Remove the tape’s backing paper and then press the adhesive side of the foam into the window base, along the seal. Use the same process to seal the sides of the sash if the draft is coming through that way, placing the foam into the v-channels where the sliding sash runs up and down as you open and close the window.
- 4). Feel around the frame of the window for drafts after sealing the sash and windowpane. Seal a leaky frame from the outside by measuring each side of the frame, cutting fiberglass batting to fit the measurements with a utility knife, and then filling in the sides of the trim against the wall of the structure with the batting. Apply a bead of caulking around the frame of the window over the batting, and smooth the bead in place by pressing it with your wet fingertip for a more attractive appearance.
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